In industrial production or assembly processes, there is a need to turn over the workpiece in order to process the opposite sides of the workpiece. A conventional turnover mechanism includes a bracket and a turnover module rotatably mounted on the bracket. The turnover module can hold the workpiece tightly by sucking one surface of the workpiece. When the turnover module is rotated 180 degrees, the workpiece is rotated 180 degrees with the turnover module.